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We present new computations of the equilibrium and non-equilibrium cooling efficiencies and ionization states for low-density radiatively cooling gas containing cosmic abundances of the elements H, He, C, N, O, Ne, Mg, Si, S, and Fe. We…

Astrophysics · Physics 2009-11-11 Orly Gnat , Amiel Sternberg

Theoretical calculations of the cooling potential of radiative cooling materials are crucial for determining their cooling capability under different meteorological conditions and evaluating their performance. To enable these calculations,…

Atmospheric and Oceanic Physics · Physics 2021-08-19 Jyotirmoy Mandal , Xin Huang , Aaswath P. Raman

We present ion-by-ion cooling efficiencies for low-density gas. We use Cloudy (ver. 08.00) to estimate the cooling efficiencies for each ion of the first 30 elements (H-Zn) individually. We present results for gas temperatures between 1e4…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Orly Gnat , Gary J. Ferland

This work presents a new plasma cooling curve that is calculated using the SPEX package. We compare our cooling rates to those in previous works, and implement the new cooling function in the grid-adaptive framework `AMRVAC'. Contributions…

Astrophysics of Galaxies · Physics 2009-11-26 K. M. Schure , D. Kosenko , J. S. Kaastra , R. Keppens , J. Vink

I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion…

Astrophysics of Galaxies · Physics 2017-07-05 Orly Gnat

In this paper, we present a new calculation of composition-dependent radiative cooling and heating curves of low-density gas, intended primarily for use in numerical simulations of galaxy formation and evolution. These curves depend on only…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Sven De Rijcke , Joeri Schroyen , Bert Vandenbroucke , Natalie Jachowicz , Jeroen Decroos , Annelies Cloet-Osselaer , Mina Koleva

Cooling of particles to mK-temperatures is essential for a variety of experiments with trapped charged particles. However, many species of interest lack suitable electronic transitions for direct laser cooling. We study theoretically the…

Sympathetic cooling of trapped ions has become an indispensable tool for quantum information processing and precision spectroscopy. In the simplest situation a single Doppler-cooled ion sympathetically cools another ion which typically has…

Atomic Physics · Physics 2013-05-30 Jannes B. Wübbena , Sana Amairi , Olaf Mandel , Piet O. Schmidt

The simulation of vibrational energy transport and quantum thermodynamics with trapped ions requires good methods for the estimation of temperatures. One valuable tool for this purpose is based on the fit of dark resonances in the…

We discuss recent improvements in the calculation of the radiative cooling in both collisionally and photo ionized plasmas. We are extending the spectral simulation code Cloudy so that as much as possible of the underlying atomic data is…

High Energy Astrophysical Phenomena · Physics 2015-06-12 M. L. Lykins , G. J. Ferland , Ryan L. Porter , Peter A. M. van Hoof , R. J. R. Williams , Orly Gnat

The hydrogen plasma is studied at temperatures T ~ 10^4 - 10^6 K using the free energy minimization method. A simple analytic free energy model is proposed which is accurate at densities up to 1 g/cc and yields convergent internal partition…

plasm-ph · Physics 2009-10-30 A. Y. Potekhin

This work follows Lykins et al. discussion of classic plasma cooling function at low density and solar metallicity. Here we focus on how the cooling function changes over a wide range of density (n_H<10^12 cm^(-3)) and metallicity (Z<30Z…

Instrumentation and Methods for Astrophysics · Physics 2014-05-12 Ye Wang , G. J. Ferland , M. L. Lykins , R. L. Porter , P. A. M. van Hoof , R. J. R. Williams

The pursuit of high optical depth and long coherence time in atomic ensembles faces a fundamental thermodynamic constraint: heating enhances light-atom coupling via increased density but degrades coherence through thermal broadening, while…

Atomic Physics · Physics 2025-05-06 Changhao Cheng , Jinxian Guo

Nonequilibrium (time-dependent) cooling rates and ionization state calculations are presented for low-density gas enriched with heavy elements (metals) and photoionized by external ultraviolet/X-ray radiation. We consider a wide range of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Evgenii O. Vasiliev

In the collisionless plasmas of radiatively inefficient accretion flows, heating and acceleration of ions and electrons is not well understood. Recent studies in the gyrokinetic limit revealed the importance of incorporating both the…

High Energy Astrophysical Phenomena · Physics 2023-08-11 Kaushik Satapathy , Dimitrios Psaltis , Feryal Ozel

Context. The radiative energy balance in the solar chromosphere is dominated by strong spectral lines that are formed out of LTE. It is computationally prohibitive to solve the full equations of radiative transfer and statistical…

Solar and Stellar Astrophysics · Physics 2015-06-04 Mats Carlsson , Jorrit Leenaarts

We study hydrogen plasmas at magnetic fields B ~ 10^{12}-10^{13} Gauss, densities ~ 10^{-3}-10^3 g/cc and temperatures T ~ 10^{5.5}-10^{6.5} K, typical of photospheres of middle-aged cooling neutron stars. We construct an analytical free…

Plasma Physics · Physics 2009-10-31 A. Y. Potekhin , G. Chabrier , Yu. A. Shibanov , J. Ventura

In this paper we study the role of radiative cooling in a two-fluid model consisting of coupled neutrals and charged particles. We first analyze the linearized two-fluid equations where we include radiative losses in the energy equation for…

Solar and Stellar Astrophysics · Physics 2024-03-19 Beatrice Popescu Braileanu , Rony Keppens

Our knowledge about the "cold" Universe often relies on molecular spectra. A general property of such spectra is that the energy level populations are rarely at local thermodynamic equilibrium. Solving the radiative transfer thus requires…

Instrumentation and Methods for Astrophysics · Physics 2018-01-23 Jérôme Loreau , François Lique , Alexandre Faure

The effects of radiation on the structure of shocks in a fully-ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity…

High Energy Astrophysical Phenomena · Physics 2016-03-28 Bryan M. Johnson , Richard I. Klein
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